Handy tips on making your caravan fridge
run more efficiently on 12 volt or 240 volt.
What types of refrigeration do they use in vans and
The most common type of refrigerator in
caravans, motorhomes and fifth-wheelers
absorption refrigerator. It is called three
way as it has three alternative power sources ie: 12V/
LPG gas. Some
of these refrigerators have a climate class rating and
Climate Class ‘T’ refrigerators are
designed to work in tropical climates where the
temperatures up to 43 degree C. For more information
see the foot of this page.
'Three way' refrigerator systems are now
available in manual (MES) and fully automatic (AES)
energy source selection with the fully automatic system
first seeking 240 volt (mains power) if it is available
and, if not, then seeks LPG or lastly 12V.
The standard mobile refrigeration in the
majority of RVs is a small capacity door fridge/freezer.
It has a small freezer section, not much bigger than a
shoe box, that will hold little more than ice trays.
For the long term traveller smaller refrigerators are
not sufficient. Some travellers use a portable
chest refrigerator such as an Engel or
which can be placed in the back of the vehicle/4WD as
additional fridge/freezer use.
Dometic Australia has
released a new 8 series model refrigerators (R8501 and
RML8551) with a removable freezer compartment. A clip
system facilitates quick and simple removal of the freezer
compartment that then allows the expanded refrigerator area
to be used as a cooling compartment. Power consumption is
also reduced by removing the freezer.
The ‘three way’ refrigerator must be in a
reasonably level position to operate as the gas
‘absorption’ cooling components and process is dependant
on the refrigerator being level in both directions.
Remember to have regular maintenance carried
out on your LPG refrigerator as parts can be subject to wear
through vibration and age.
Dometic gas refrigerators have an automatic
flame failure device that shuts off gas flow if the flame is
extinguished and they have a gas indicator showing when gas
is lit. This is a safety feature to prevent carbon monoxide
Carbon monoxide (CO) is an odourless,
tasteless, invisible gas produced when LPG gas and other
fuels like oil, kerosene and wood are burnt. Do not block
the ventilation panel located in the bottom of the door to
your RV as this lets any gas escape. As a safety
precaution, in case a gas appliance ceases to work properly
or the cowl is faulty, install a carbon monoxide detector or
CO alarm. Information researched indicates a CO alarm needs
to be replaced when the sensor wears out and this may only
take a couple of years although manufacturers of the
SafeTAlert carbon monoxide detector and alarm state their
product is a long life, self cleaning, maintenance free
type of refrigerator used in RV’s is the
12V/ 240V compressor refrigerator/freezer. Two
popular brands of this type are VitroFrigo and Waeco /
CoolMatic Danfoss Kompressor fridges. The capacity of these
refrigerator/freezers range from 40 litres up to 230
litres. There are models featuring two doors ie: one for
the large freezer compartment and the other for the
For example the Waeco RPD 190 upright
compressor is a 140 litre refrigerator and a 45 litre
freezer which operates on 12V or 24V DC. It runs off a
Danfoss BD-50F Kompressor with a temperature range up to 50
degrees below ambient . It has an internal light, adjustable
shelves, vegetable compartments and the doors (with patented
door locks) can be adapted for left hand or right hand
opening. Depth 610mm x width 590mm x height 1340 mm
(including flush mount frame) and it weighs approx 45kg.
Vitrifrigo compressor refrigerators are
Italian designed 12V/24V caravan and motorhome refrigerator
with an option for automatic cutover to 240V when connecting
to mains power
via a mobitronic. However, the trend these
days is to have the compressor refrigerator wired direct to
the 12V battery bank and the batteries are charged whilst on
240V mains power or from solar panels.
The Vitrifrigo DP 2600 is a 240 litre
fridge/freezer (180 litre refrigerator and 60 litre
freezer) with flush mounted surrounds that runs off a
Danfoss BD50F compressor. It has an internal light,
adjustable shelves, vegetable compartments and the doors can
be adapted for left hand or right hand opening. This
Vitrifrigo refrigerator weighs 64.5kg and most of this
weight is attributed to the insulated wall thickness of
50mm, the freezer insulation of 70mm and freezer door
thickness of 90mm. The dimensions are
590W x 580D x H1335.
Average power consumption – 40W/H.
Defrosting should be done whenever the frost
layer exceeds a thickness of about 3mm as cooling efficiency
can decrease and power consumption increase. To completely
defrost the refrigerator turn the thermostat knob to
‘stop’. Don’t use anything sharp as this could pierce the
refrigerator plate and cause irreparable damage. After
defrosting, empty the drip tray and turn the thermostat knob
to the desired setting.
One tip with the Vitrifrigo refrigerators is
not to push the drip tray too far back as it can interfere
with the flow of cool air. We find our Vitrifrigo runs best
when the thermostat knob is on about 4.2.
On 12V power the compressor refrigerators
have less draw current than the absorption refrigerators and
if your RV is connected up to solar panels it will simply be
charging off the power stored in your batteries and being
charged by the solar panel array as you are travelling.
Although manufacturers recommend these compressor
refrigerators are best operated on a level surface it is not
completely necessary as they have a tolerance up to about 30
Types and sizes of refrigerators are similar
for motor homes with the larger coach type motor home such
as the Swagman having a standard two door 230 litre 12V with
We have not gone into the intricacies of how
these absorption and compressor refrigerators actually work
mechanically. If you want to know more about how an
absorption refrigerator or a compressor refrigerator work do
a search on line as there are a number of websites with
information and diagrams.
Deep cycle batteries will be required to
store the power to run these 12V compressor refrigerators
when not connected to a 240V power source. Most RV’s with
compressor refrigerators will also have solar panel plus a
solar regulator to supply power to the batteries.
There are three types of batteries that are
most popularly used in solar electric systems
For more information on batteries see article -
Vehicle Dual Battery System
Can I run my 3-way
caravan fridge on gas while travelling ?
NOT. This is highly dangerous.
appliances must be turned off whilst your RV is under tow. Imagine what
would happen if you cut an active gas line. There are just
too many sources of ignition around, like a stone hitting a
metal part and generating a spark.
Whilst in transit your ‘three way’
refrigerator is connected to an in-house battery or power is
supplied by the tow vehicle battery/alternator. If you stop
for any length of time remember to disconnect the vehicle
from the RV as it will likely flatten the vehicle battery.
can I make my caravan fridge more efficient ?
Approximately two days before departing
on a trip or holiday, turn your RV refrigerator on at
home at the mains power as this will give the
refrigerator time to cool down to a constant
foods and drinks in your home refrigerator before
placing them in your RV refrigerator. It is best to
pack some foods in air tight plastic containers and
cover ice blocks in ice trays in the freezer.
Keep the air vents clear of any
Other tips include:-
While you have the fridge out or the covers off,
install fibreglass batts around the sides and top of
the fridge. Obtain or buy a small fan and fit it
below the condenser fins where they are hottest.
Make a curved tin top to the fridge to allow the hot
air to flow smoothly out.
Install a solar fridge fan in the vent compartment
behind your refrigerator
Install a 12V Fridgemate cooling fan - this attaches
to the bottom of the refrigerator compartment and
blows up into the coils and toward the top vent
When stationary - use some shadecloth or canvas
awning to shade the exterior of the RV where the
fridge vents are located. This is particularly
helpful for the gas type fridges.
The article from which the
on the climate class rating of
refrigerators is reproduced by express permission,
Collyn Rivers, Caravan & Motorhome Books, Broome, WA
6725. This article is protected by Copyright. www.caravanandmotorhomebooks.com
Climate Class Ratings
I to explain
here just what I mean. A number of fridges
sold in Australia are marketed as 'tropicalised'. Whilst
this is a reasonable description of their design and
construction, the term 'tropicalised' can
unintentionally mislead those not familiar with fridge
increasingly accepted European Union (CEN) fridge
performance standard, includes so-called 'Climate
Classes' in which the most stringent is Climate Class T.
And that 'T' stands for Tropical. So in the way that
'oils ain't necessarily oils', a 'tropicalised' fridge
ain't necessarily Climate Class T.
four (CEN Standard) Climate Class ratings.
rated 'SN', and 'N' (which stands for Sub Normal, and
Normal respectively) are designed and rated to work up
to 32 degrees C.
marked 'ST', (which stands for Sub Tropical) are
designed and rated to work up to 36 degrees C. Those
marked 'T' (which stands for Tropical) are designed and
rated to work up to 43 degrees C.
correctly installed fridge Climate Class rated fridge
can be relied upon to work satisfactorily up to the
highest ambient temperature for which it is rated. But
once past that temperature, cooling performance is
likely to drop off. If, for example, you have a Climate
Class SN or N fridge (ie. designed for 32 degrees
maximum), but it's 42 degrees outside, the beer in that
fridge is likely to be up to ten degrees C warmer.
So if you
are planning to spend time in places that are very hot,
it is prudent to use a 'T-rated' unit. I have yet to
encounter anyone even locally using a correctly
installed 'T-rated' fridge that was not completely
satisfied with its performance. And I live in the
Kimberley which is one of the most consistently hot
areas of this country.
that the European Union Standard that includes Climate
Class ratings is not obligatory in Australia.
Nevertheless Dometic and a few other fridge vendors
market fridges in Australia that have the 'Climate
Class' rating noted on their compliance plate (which
you'll find inside the fridge). Climate Class T fridges
were for example fitted in several display Winnebagos on
display at the Casino Rally and many CMCA members have
recently bought them.
regarding this: a statement that a fridge is
'tropicalised' does not imply that it meets Climate
Class 'T' requirements.
states that its fridges that do meet the 'T' standard
(and are designated accordingly on the compliance plate)
are the larger models RM 2453, RM 2553, and RM 4601. The
company claims only that its smaller fridges are